Wrapping machine



April 22, 1969 M- HA N ET AL 3,439,472

WRAPPING MACHINE Filed May 11. 1966 Sheet of 2 Fig. 1

April 22, 1969 'HAIN ET 3,439,472

WRAPPING MACHINE I Sheet 2 M2 Filed May 11, 1966 United States Patent Int. Cl. B65b 11/16, 49/08 U.S. Cl. 53-226 4 Claims ABSTRACT OF THE DISCLOSURE A machine for wrapping packages includes a wedge shaped element arranged to move between two positions in an arcuate path. In the first position, one side of the wedge holds one side of the wrapper while other mechanisms fold down the flap on three sides. The wedge is then shifted to the second position where the other side of the wedge forms a continuation of a flat plate in alignment with the bottom of the package so that the fourth flap will be folded over the previously folded flaps when the pack age is moved away in a path paralllel with the plate.

This invention relates to a device for closing the wrappers of articles, particularly block-shaped articles, by tucking in the rearwardly extending portions of the wrapper folded in the preceding folding channel, on the backside of the article.

In wrapping machines of the type here involved, the closing mechanism follows immediately the folding channel so that the articles to be wrapped are advanced one after the other by a plunger onto the closing position. In

order to complete the folding of the wrapper, the rearwardly extending flaps are tucked in by means of sequentially actuated closing bars of the closing device. As said tucked-in flaps are at the rearside of the articles, said closure side is covered by the next article, which prevents in a most simple manner a springing back of the folds. On the other hand, the superposition of the articles makes it difficult to subject the closed fold to an after-treatment such as sealing, cementing, or the like, because the closing side is not freely accessible. In addition, a separate removal of the wrapped articles is often required. I-Iowever, this is frequently not possible where the wrapper has been folded and the end fold is at the back of the article because even with very suitable wrapping material the folds must be held down for such time under pressure. In order to overcome said difficulty, heat-seal elements have been provided for cooperation with the folding plates or bars. However, such devices are complicated and allow only a spot welding of the flaps.

It is, therefore, a principal object of the invention to provide an end folding apparatus for partially wrapped articles which allows conveying the wrapped articles separately to a next station immediately after the flaps have been tucked in and while maintaining the pressure exerted in the folded flaps and sealing said flaps.

Other objects and advantages will be apparent from a consideration of the specification and claims.

In accordance with the invention, we provide a support plate which carries the articles in the end folding operations and is separate from the conveyer; after the end flaps have been tucked in, said support plate can be pivoted along a gliding plane onto the slot formed by two vertical conveyer belts.

Such a support plate which can be pivoted along a gliding surface allows delivering the completely wrapped articles without releasing the end fold and in exactly spaced relationship to a conveyer for further treatment.

In a preferred embodiment of the invention, the closing means for the end flap forms with a hold down face a rotatable wedge whose actuating surfaces are brought into operative position by raising or lowering and rotation.

Said double function of the wedge provides for a compact and simple construction of the end folding mechanism whereby the up-swinging of the wrapped articles from the end folding position shorten the wrapping path.

The use of conveyer belts driven around vertical axes has the further advantage that the belts cannot sag and exert from both sides a homogeneous pressure on the articles. In this way, it is easy to provide sealing means at one of the belts.

The invention will now be described in greater detail in connection with a preferred embodiment shown in the accompanying drawings in which:

FIG. 1 is a perspective view of the end folding mechanism after the first step before being moved on;

FIG. 2 is the same view, after the second step; and

FIG. 3 is a perspective view of the transfer device showing a wrapped article in the swing position.

. The end folding device shown in FIGS. 1 and 2 comprises a support plate 1 for the articles 2 coming from the conventional folding channel lying behind the plane of the drawing (not shown). In this position, the articles are partially wrapped, the end flaps still rearwardly projecting. The support plate 1 is carried by a swivel arm 3 which is swingable in a vertical plane. The swinging motion is carried out in accordance with the folding operation and the advance of the articles. A stop plate 4 at the front end of the support plate 1 limits the advance motion of the articles and holds the same in the end folding and swing position.

A bottom tucker 7, a front side tucker 8, and a second side tucker 9 tuck in the rearwardly extending flaps 5, said tuckers are actuated by push rods 11, 12 and 13 guided in guides 14, 15 and 16. Said tuckers move closely along the rearside of the article and thereby fold the flaps inwardly. Generally, the bottom tucker 7 is advanced first (FIG. 1) to tuck in the bottom flap. Following the return stroke of the bottom tucker, both side tuckers 8 and 9 can engage the side flaps simultaneously. During these operations, the top face of the articles 2, is held by a hold down face 21 which, in the illustrated embodiment of the invention, is combined with an end folding tucker 22 to a rotary wedge 20. Said rotary wedge is mounted resiliently upwardly so as to be adaptable to articles of different sizes. In order to place the end tucker 22 in operative position, the rotary wedge is raised and turned so far that the tucker 22 is located in the folding plane (FIG. 2).

For this purpose, the base 23 of the rotary wedge is connected to a push rod 24 reciprocating in a guide 25. A lift arm 26 engages a lug 27 of said push rod 24 and thereby lifts the push rod and the rotary wedge base 23. The to tary wedge is so mounted as to be able to perform a turning movement in a clockwise direction as viewed in FIGS. 1 and 2, this movement being guided by the engagement of the rollers 28 (FIG. 2) with the arcuate tracks 31 (FIG. 1) during the lifting movement. The lift and turning motion of the rotary wedge is assisted by the two lateral draw springs 29. Draw springs 30 acting on the push rod 24 ensure the return movement of the rotary wedge into the starting position, when the lift arm 26 moves again downwardly.

When also the bottom and side flaps have been tucked in and the rotary wedge has turned onto the folding position (FIG. 2), then the support plate 1 starts its pivotal motion (FIG. 3). There, also the upper flap 18 is folded by means of the stationary tucker 22. As said last folded flap covers the other flaps, there is no risk that in the upswing of the article and the preceding withdrawal of the side tuckers, the flaps will stand up again. As will be seen in viewing FIG. 3, the tucker 22 is followed by a slide surface 33 which continues holding down the flaps. If the stop plate 4 is mounted resiliently, a further stop for the side of the article which looks downward during the swing manipulation, can be omitted.

The support plate 1 conveys the wrapped article along the slide surface 33 in between the vertical rotating belts 40, 42. 41 and 43 are some of the verticle rollers driving said belts. The slide surface 33 projects so far in the transport gap 44 as to ensure the gripping of the article 2 when it is swung upwardly. In the illustrated embodiment, the belt 40 consists of a heat resistant heat conductive material in order to transmit the heat and pressure required for sealing the wrapper from a heating element disposed inside the belt. The sealing then takes place during the transport movement. The counterbelt 42 consists preferably of an elastic material such as foam rubber or the like. The gap 44 is so arranged as to apply a slight pressure to the article during the transport. This not only improves the fold and seal but prevents also dropping or tilting of the articles.

While we have shown and described certain embodiments or our invention, it is to be understood that it is capable of various modifications. For instance, instead of the convention tuckers moving in a straight line, they may be so arranged for pivoted motion. The operative surfaces 21 and 22 of the rotary wedge 20 may be separated and provided as independent actuators. In such a case, the connecting end of the sliding surface 33 itself can take over the function of a tucker, whereby the hold down face 21 would have to be removed from the swing path by lifting or folding back.

We claim:

1. In combination with an article wrapping machine, an end flap folding mechanism for completing the wrapping of a partially wrapped article having four side flaps projecting outwardly from around the four side margins of the bottom side of the article said side flaps to be folded inwardly and downwardly upon said bottom side comprising supporting means for holding said partially wrapped article on one of said four sides, said supporting means being pivotally mounted for moving said article in an arcuate path in a plane parallel with the plane of said bottom side between a first and a second position, means for folding three of said side flaps inwardly upon said bottom side while the article is in said first position, a wedge-shaped element having first and second flap surfaces intersecting in a marginal edge,-means for mounting the wedge-shaped element for movement between a first position wherein said first surface is positioned against the side of the article opposite the side on which the article is supported in said first position of the supporting means, said mounting including means for swinging the wedge-shaped element in an arcuate path to a second position wherein said second surface is disposed substantially in the plane of the bottom side of the article with said marginal edge adjacent the fourth side flap to be folded, a fixed plate positioned in the plane of said bottom side and forming with the second surface of the wedge-shaped element a substantially continuous surface for folding the fourth side flap when said article is moved by the supporting means from said first position, and a pair of conveyor belts arranged for receiving said wrapped article from the supporting means in said second position.

2. The invention defined in claim 1, wherein said means for folding said first three flaps inwardly comprise a plurality of tuckers mounted for reciprocating movement in directions disposed in a plane parallel with said bottom side of an article 3. The invention defined in claim 2, wherein said mounting for the wedge-shaped element includes arcuate track means, roller means on said wedge-shaped element for operative engagement with the track means, and reciprocating push rod means connected with the wedgeshaped element for moving said element between said first and second position.

4. The invention defined in claim 1, wherein said supporting means for the article is provided with stop means for limiting movement of said article in a direction normal to the plane of said fixed plate for aligning the bottom side of the article with said plate.

References Cited UNITED STATES PATENTS 1,182,755 5/1916 CoWen 53-387 X 1,824,378 9/1931 Smith 53-223 X 1,915,499 6/1933 Langhammer 53-223 X THERON E. CONDON, Primary Examiner.

N. ABRAMS, Assistant Examiner.

US. Cl. X.R. 53--230 

